A slide fastener is generally used as an opening and closing tool of an article such as clothes, daily sundries, industrial materials and the like or an article such as various seats of a vehicle, a train, an airplane and the like. In general, the slide fastener used for an opening and closing part of the various articles has a pair of fastener stringers each of which has an element row, and a slider arranged to be slidable along the element rows.
As the fastener stringer, there are generally known a fastener stringer of which an element row is formed by forming a mono filament made of thermoplastic resin into a coil shape or zigzag shape and sewing continuous fastener elements, which have a plurality of engaging heads continuously coupled into one, to a fastener tape, and a fastener stringer of which an element row is formed by directly injection molding single elements made of a synthetic resin to a string-shaped fastener tape.
Also, for example, International Patent Application Publication No. WO2012/020499 (Patent Document 1) discloses a slide fastener 70 having fastener stringers 71 as shown in FIGS. 18 and 19.
The slide fastener 70 disclosed in Patent Document 1 has a pair of right and left fastener stringers 71 each of which has an element row 72 formed on a fastener tape 73, a slider 80 configured to be slidable along the element rows 72, first end stops 78 arranged at one end portions of the right and left element rows 72 and a second end stop 79 arranged at the other end portions of the right and left element rows 72.
In this case, a front and rear direction indicates a tape length direction of the fastener tape 73. In particular, a direction along which the slider 80 slides to engage the element rows 72 of the slide fastener 70 is referred to as front, and a direction along which the slider slides to disengage the element rows 72 is referred to as rear. Also, a right and left direction indicates a tape width direction of the fastener tape 73. Further, an upward and downward direction indicates a tape front and back direction of the fastener tape 73. In particular, a direction of a side of the fastener tape 73 on which a pull tap 81 of the slider 80 is arranged is referred to as an upward direction and an opposite direction thereto is referred to as a downward direction.
Each of the right and left fastener stringers 71 has the string-shaped fastener tape 73 and a plurality of fastener elements 90 arranged on a first surface of the fastener tape 73. The plurality of fastener elements 90 is sewed to the first surface of the fastener tape 73 by a double chain stitch of two sets of sewing threads (not shown) with being connected to each other by two connecting string-shaped members (for example, connecting threads) 91.
Each fastener element 90 is configured by injection molding the synthetic resin to the two connecting string-shaped members 91. Each fastener element 90 has a body portion 92 fixed to the two connecting string-shaped members 91 and an extension portion 93 extending outwardly (towards the engaging matching fastener stringer 71) in the tape width direction from the body portion 92. The extension portion 93 has a first extension portion 93a arranged at a side facing the first surface of the fastener tape 73 and a second extension portion 93b arranged at a side exposed to the external and having a different shape from the first extension portion 93a. 
In this case, an upper surface portion, a front end surface portion and a rear end surface portion of the body portion 92 of the fastener element 90 are formed with two recessed accommodation grooves for accommodating sewing threads to sew the fastener element 90 to the fastener tape 73 so that the recessed accommodation grooves are positioned between the two connecting string-shaped members 91. Also, the first extension portion 93a has a neck portion 94 extending in the tape width direction from the body portion 92 and having a narrowed shape and an enlarged engaging head 95 further extending from the neck portion 94. The second extension portion 93b has a substantially triangular shape of which a size in the tape length direction (front and rear direction) gradually decreases towards a tip portion thereof, as seen from above.
According to the fastener stringer 71 having the above-described configuration disclosed in Patent Document 1, the two sets of sewing threads to sew the fastener element 90 are accommodated in the recessed accommodation grooves of the fastener element 90 and sew and fix the fastener element 90 to the fastener tape 73. Therefore, the fastener element 90 is securely fixed by the sewing threads and the sewing threads are prevented from being separated from the fastener element 90. For this reason, the fixing strength of the fastener element 90 to the fastener tape 73 is improved.
Also, each fastener element 90 connected by the two connecting string-shaped members 91 is sewn by the double chain stitch of the two sets of sewing threads. Therefore, it is possible to stably attach each fastener element 90 to the fastener tape 73.
Further, according to the fastener stringer of the related art where the fastener elements made of synthetic resin are directly injection-molded to the fastener tape, the fastener elements are usually formed over front and back surfaces of the fastener tape. However, according to the fastener stringer 71 of Patent Document 1, the fastener elements 90 injection-molded and made of synthetic resin are arranged only on one tape surface-side of the fastener tape 73. For this reason, according to Patent Document 1, it is possible to lighten the fastener stringer 71 having the injection molded fastener elements 90 and to increase the flexibility of the fastener tape 73 (particularly, the flexibility in the tape front and back direction).
Also, for example, International Patent Application Publication No. WO2009/118846 discloses a concealed slide fastener having fastener stringers configured by injection molding a synthetic resin to connecting string-shaped members.
According to the general slide fastener (fastener stringer) of the related art, the coil-shaped continuous fastener elements or injection molded single fastener elements are attached to a tape side edge portion (element attachment portion) of the fastener tape.
In contrast, for example, Japanese Patent Application Publication No. Sho 62-299205A (Patent Document 3) discloses that in order to improve an appearance (outward appearance quality) of a coloring and the like of an article (article with a slide fastener affixed thereto) with a slide fastener affixed thereto or to lighten the article, when weaving or knitting a cloth of the article, fastener elements are directly woven and fixed or knitted and fixed to the cloth, so that the fastener elements are directly attached to the cloth of the article without a fastener tape.
When the fastener elements are directly woven or knitted to the cloth of the article, it is possible to reduce the number of operating processes in the production of the article with the slide fastener affixed thereto, as compared to a configuration where after the slide fastener is produced, a fastener tape of the slide fastener is sewn to the cloth of the article to produce an article with a slide fastener affixed thereto. For this reason, it is possible to expect the speed-up of the production line and to save the cost.
Further, since it is possible to weave and fix or to knit and fix the fastener elements to the cloth of the article with an exact attachment pitch, it is possible to smoothly perform the opening and closing operation of the slide fastener (an operating of engaging and disengaging the fastener elements).